Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is an improvement
of my Canadian patent No. 1,045,900, dated January
9, 1979, which describes and claims a mobile track
tamper comprising a frame arranged for mobility on
a track consisting of a multiplicity of ties and two
rails fastened to the ties. A tamping head is ver-
tically movably mounted on the frame in vertical `
alignment with a respective one of the rails, and a
power drive moves the tamping head vertically. The
tamping head includes a pair of rigid ballast ~-~
tamping tool implement units arranged for reciprocation
in the direction of track elongation towards and away
from each other and capable of tamping ballast under
respective ones of the ties upon vertical downward
movement of the tamping head and immersion of the tamp-
ing tools in the ballast adjacent the respective ties. -
The tamping tool implement units are mounted on a
carrier and drive means are mounted on the carrier and
connected to the units for vibrating and reciprocating
the tamping tool implement units. Each unit consists
essentially of a tamping tool holder having an arm
having a longitudinal plane of symmetry and mounted on
the carrier for pivoting in a plane vertical to the
track and passing through the rail, the longitudinal
plane of symmetry of the tamping tool holder arm extending
in the vertical plane and the holder arm being connected
to the drive means, and two arms extending transversely of
the track and rigidly connected to the vertically extending
arm to the left and to the right of the vertical plane,
and at least one stationary tamping tool mounted
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on each of the transversely extending holder arms and
extending vertically downwardly from the holder
arms for immersion in the ballast to the left and to
the right of the rail.
The rigid tamping tool implement unita of patent
No. 1,045,900 provide strong and robust tamping
tools providing a longer operating life than tamping
tools heretofore available and also increasing the
tamping effectiveness. This type of construction has
the particular advantage of providing a greatly simpli-
fied tamping tool structure with a common vibrating and a
common reciprocating drive for the tools immersed in the
ballast right and left of the rail, the force of the drive
being transmitted to the tamping tools immersed in the ballast
during tamping almost without play.
U.S. patent No. 3,589,297, dated June 29, 1971,
discloses a mobile track tamper with reciprocating vib-
ratory tamping tools of a generally conventional type
and providing an improved lubricating system for the ex-
tensive lubrication of the tamping tool bearings. In
this system, the pivoting bearings of the tamping tools
and the reciprocating drives therefor are housed, at
each side of the rail, in respective housings defining
oil sumps in the lower portions thereof. The tamping
tool holders extend from the housing and gasket seal
off the passages in the housing through which the
holders extend to prevent oil leakage. All lubricating
points outside the housing are lubricated by a central
lubricating system.
It is the primary object of this invention to provide
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a ~imple and dependable lubrication for rigid tamping
tool implement units of the type hereinabove described
and simultaneously to reduce the operating noise of such
tamping units, thuæ further enhancing the capacity and
the operating life of the unitæ. ~ ~ -
The above and other objects are accomplished in
accordance with the invention with a drive means com-
prising an eccenter shaft and reciprocating elements
connected respectively to the eccenter shaft and to
the tamping tool implementæ, a housing on the carrier
through which the eccenter shaft extends and defining
an oil sump in the lower portion thereof, bearings
rotatably mounting the eccenter shaft in the housing,
the bearings being lubricated by the oil from the æump,
and the outer ends of the reciprocating elements being
connected to the vertical arm of the holder, extending
from the hou~ing and being guided therein in a manner
substantially preventing oil leaking from the housing.
Since the rigid tamping tool implement unit re-
quires only a æingle vibrating drive and the reciprocating
drives for the tamping tools immersed in the ballast to the
left and to the right of the rail are mounted on the vibrating
drive, the housing holding the eccenter shaft drive can be
readily constructed as a sealed oil container. Furthermore,
since only two reciprocating drives are required, they may
be journaled to the eccenter shaft between the two bearings
mounting the shaft for rotation in the housing in close æpatial
relationship, thuæ making for a very cômpact structure.
This makes the
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lubrication of all bearings by the oil from the
sump very simple, these bearings being subject to
considerable loads during the vibratory and reciprocatory
movements of the tamping tools while immersed in the
ballast.
The lubrication of all lubricating points of the
rigid tamping tool implement units outside the housing
may be effected in a known manner from a central lub-
ricating system. The mounting of the moving parts of
the drive means in the oil-containing housing damps the
operating noise.
The above and other objects, advantages and features
of the present invention will become more apparent from
the following detailed description of a now preferred
embodiment thereof, taken in conjunction with the
accompanying drawing wherein
FIG. 1 is a side elevational view of a tamping head
vertically movably mounted on the frame of a mobile
track tamper,
FIG. 2 is a front elevational view of the tamping
head, and
FIG. 3 is a section along line III-III of FIG. 1, on
an enlarged scale, and
FIG. 4 is a side elevational view showing a mobile
track tamper incorporating the tamping~head of this
invention.
Referring now to the drawing, tamping head 1 is
shown mounted on frame 44 of mobile track tamper 42
arranged for mobility on a track consisting of a multi-
plicity of ties 3 and two rails 2 fastened to the ties.
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.:.
The tamping head comprises carrier 4 whereon the tamping ~ ~:
tool implements are mounted and the carrier has mounting
bracket 5 vertically slidable along two vertical guide
columns 6 of machine frame 44 so that the tamping head
is vertically movably mounted on the frame in vertical
alignment with a respective one of rail~ 2. A power
drive con~tituted by hydraulic motor 45 connects the
carrier to the frame for vertically moving the tamping
head along the vertical guide columns. This arrangement
0 i9 generally similar to that of the above-mentioned co-
pending patent application, as are the tamping tool
implements arranged on each tamping head, a respective
tamping head being mounted on the machine frame over each
rail although only a single one is shown in the drawing. ~-
'. As has been described in the prior application,
each tamping head includes a pair of tamping tool imple-
ment~ arranged for reciprocation in the direction of.
track elongation towards and away from each other and
capable of tamping ballast under re~pective ones of
ties 3 upon vertical downward movement of the tamping
head and immersion of the tamping tool implements in -~
.
the ballast adjacent the respective ties. Drive means
comprising eccenter shaft 16 for vibrating the tamping
tool implements and hydraulic motors 18 for reciprocating
the same are mounted on carrier 4, tXe reciprocating
~: motors having outer ends 19 linked to the tamping tool .- implements and inner ends 20 linXed to the eccenter shaft~
Each tamping tool implement is constituted by a rigid
unit consisting essentially of tamping tool holder 7
having arm 10 having longitudinal plane of symmetry 11
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and mounted on carrier 4 on pivot axis 9 for pivoting in a
plane vertical to the track and passing through the rail, the
longitudinal plane of symmetry of the tamping tool holder arm
extending in the vertical plane and the holder arm being con-
nected to outer end 19 of a respective one of the piston rods
of hydraulic reciprocating motors 18, two arms 12 extending
transver~ely of the track and rigidly connected to vertically
extending arm 10 to the left and right of vertical plane 11,
and two stationary tamping tools 13 mounted on each transversely
extending holder arm 12. The tamping tools extend vertically
downwardly from the holder arm~ for immersion of their tamping
jaws 14 in the ballast to the~left and to the right of rail 2.
In accordance with the invention, sealed housing 15
is mounted on carrier 4 between support webs 8 thereof and
eccenter shaft 16 extends therethrough, the eccenter shaft being
driven by hydraulic motor 17 for vibrating the tamping tool im-
plements. As best shown in FIG. 1, each rigid tamping tool im-
plement unit is reciprocated by a single hydraulic motor 18
having a reciprocating piston rod whose outer end 19 is linked
to holder arm 10 while the inner end 20 of its cylinder is linXed
to the eccenter shaft. Bearings 36, 37 and 38 rotatably mount
eccenter shaft 16 in housing 15 while bearings 34 mount the
hydraulic reciprocating motors on the eccenter shaft. Elastic,
substantially bellows-shaped sealing sleeves 21 have respective
ends affixed to housing 15 and the outer ends of the cylinders
of hydraulic motors 18, which cylinders extend through bores in
the housing. The cylinders guide the reciprocating piston rods
out of housing 15 and the sealing sleeves prevent oil from leaking
from the housing which defines oil sump 22 in the lower portion
thereof. The bearings are lubricated by the oil from the sump.
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The sealing sleeveæ illustrated herein for preventing
any substantial leakage of oil from the hou~ing are commer-
cially available sealing device~ which are relatively inexpen- -
sive and have a long operating life under repeated expansion
and retraction by the constantly reciprocating movements of
the piston rodq. Such sealing sleeves can be readily re-
placed when worn out.
A particularly useful system for lubricating the bearings
of the drive means constituted by the hydraulic vibrating and
reciprocating motors by the oil from sump 22 has been illustrated
in FIG. 3. This system comprises pump 23 which has an input in
communication with the oil sump and an output in communication
with the bearings for pumping oil from the sump to the bearings.
In the illustrated embodiment, lubricating oil is delivered by
pump 23 to all the bearings and lubricating point~ within housing
15. For this purpose, cover 28 of housing 15 carries a bank of
downwardly oriented spray nozzles 29 and 30 which are in
communication with oil main 31 passing through the cover and re-
ceiving oil from the output of pump 23 through connecting conduit
32 (shown in broken line). Inner ends 20 of hydraulic motors
18 have a split sleeve mounted on bearings 34 and defining
spaces 33. The split sleeves have radially projecting and
axially spaced rings which interdigitate. Spray nozzles 30 are
so oriented a~ to spray oil into spaces 33. In this manner,
roller bearings 34, which mount the inner ends of the hydraulic
reciprocating motors on the eccenter shaft and which require a
great amount of lubrication, receive a constant supply of lub-
ricating oil and are cooled thereby. Outer spray nozzles 29
are so oriented as to spray
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oil into spaces 35 located between roller bearings 34
and neighboring bearingq 36 and 37 of the eccenter
shaft in housing 15, thus conqtantly lubricating these
bearings.
The use of an oil delivery pump for lubricating
the bearings is more advantageous than submerging the
bearings in the oil sump because it enable~ each
bearing to be lubricated by a required amount of oil
and, in addition, no loss of power is encountered by
mounting rotating parts in the oil bath. The provision
of spray nozzles ha~ the particular advantage of form-
ing a continuous lubricating film on the bearings and,
furthermore, the oil sprays will provide a cooling effect
which increases the operating life of the bearings by
the avoidance of overheating.
In the illustrated embodiment and preferably, pump
23 i~ driven by eccenter shaft 16. For this purpose, a
transmission connects the eccenter shaft to the pump -~
shaft for driYing the pump, the illustrated tran~mis~ion
being a V-belt drive arranged outside housing 15. This
drive comprise~ pulley 24 mounted at an end of the pump
shaft outside housing 15, pulley 27 keyed to the ecc-
enter shaft outside the housing, and V-belt 26 trained -
over the pulleys, tension roller 25 holding the belt
under the required tension. Such a transmission is very
advantageous since the driving power of the pump is
quite small in comparison to the required power of
the eccenter shaft. ~herefore, there is no need to
increase the power of vibrating motor 17 and the pump
can be driven without an additional power source.
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The third bearing 38 of the eccenter shaft outside
housing 15, between bearing 34 and motor 17~is lubricated
by the oil from 9ump 22 through branch conduit 39 leading
from conduit 32 to bearing 38.
Gasket 40 ~eals the bore in housing 15 through which
eccenter Qhaft 16 extends and the opposite bore in the
housing is Qealed by cap 41 so that ~ubstantially no oil
can leak from the housing at the points where the ecc- -
enter shaft pas~es out of the housing. Spray nozzles
29 and 30 lubricate all points of hydraulic reciprocating
motors 18 within the housing which require lubrication.
Housing 15 is easily made substantially leak-proof
since seals are required only at the two points where
the eccenter shaft passes through the housing wall and
the two points where the hydraulic reciprocating motors .-
pass therethrough:~. The oil in the housing and the loca-
tion of the eccenter shaft therein, as well as of the bear-
ings of the hydraulic reciprocating motors thereon, damps
the otherwise considerable noise of the tamping tool imple- ..
ments during operation.
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